Clinical History:
24 year old female
with history of biopsy proven membranous
nephropathy, who had partial remission with x2
recurrences. Rapidly progressive CKD (creatinine = 5.8
mg/ dL). All autoimmune serology is negative but she has
low C4 (<8 and 12.6mg/dL) which is suggestive of C4
glomerulonephritis.
Histology: Glomeruli
demonstrate mild to moderate mesangial matrix expansion
with minimal increased cellularity, as evaluated by PAS
stain (Figure A). There is thickening of capillary loop
basement membranes. There is also thickening of Bowman’s
capsule and trichrome stain highlights severe
interstitial fibrosis with associated tubular atrophy
(Figure B).
Special Immunohistochemical stain for C4d
shows glomeruli with abundant positive granular deposits
(Figure C, D) |